package com.iceberg;

import java.util.TreeMap;

public class Trie {

    private class Node{

        public boolean isWord;
        public TreeMap<Character, Node> next;

        public Node(boolean isWord){
            this.isWord = isWord;
            next = new TreeMap<>();
        }

        public Node() {
            this(false);
        }

    }

    private Node root;
    private int size;

    public Trie(){
        root = new Node();
        size = 0;
    }

    public int getSize(){
        return size;
    }

    public void insert(String word){

        Node cur = root;
        for (int i = 0; i< word.length(); i++){

            char c = word.charAt(i);
            if (cur.next.get(c) == null){
                cur.next.put(c, new Node());
            }
            cur = cur.next.get(c);
        }
        if (!cur.isWord){
            cur.isWord = true;
            size ++;
        }
    }

    public boolean search(String word){

        Node cur = root;
        for (int i = 0; i < word.length(); i++){
            char c = word.charAt(i);
            if (cur.next.get(c) == null){
                return false;
            }
            cur = cur.next.get(c);
        }
        return cur.isWord;
    }

    public boolean startsWith(String prefix){
        Node cur = root;
        for (int i = 0; i < prefix.length(); i++){
            char c = prefix.charAt(i);
            if (cur.next.get(c) == null)
                return false;
            cur = cur.next.get(c);
        }
        return true;
    }

    public static void main(String[] args) {

    }
}
